Refrigerating apparatus



. May 22, 1928.

, 1,670,868 R. c. PIERCE v REFRIGERATING APPARATUS 3 Filed. Nov. 15- 1920 2 Sheets-Sheet 1 Z5 v f i Q I 5 62 (T Z 9 4 t f) ,,I 64 as C I a s l I so 67 :24 v

a '1 5' i n 57 I 1 f r 19 10 v I 1 r v 5 4 5 '%y I Fig.1

INVENTORQ ATTORNEY.

May 22, 1928.

R. C. PIERCE REFRI [GERATING APPARATUS Filed Nov. 15 1920 2 Sheets-Sheet 2 INVENTOR.

A ATTORNEY.

Patented May 22, 1928.

UNITED STATES BAYIOND O. PIERCE, 01' NEW YORK, N. Y.

BEI'BIGEBLTING APPARATUS.

Application fled November 15, 1920. Serial No. 424,226.

This invention relates to refrigerating apparatus and more particularly toimprovements in small refrigerating machines for household use, it being understood that certainfeatures of the invention are adapted to be used as well in larger types of machines.

This invention relates to machines which produce refrigeration by the alternate liquefaction and vaporization of gases especially where a refrigerant of relatively large volume may be circulated preferably under arelatively low pressure. Of course, any suitable gas which may be liquefied and then vaporized may be employed.

One of the objects of this invention is to provide a machine having its compressor mounted outside the condenser chamber and heat insulated therefrom.

Another object'of the invention is to provide adequate and entirely automatic lubrication for all parts of the refrigerating machine proper.

Another object of the invention is to provide an improved liquid sealing means that may be constructed of commercial tubing which is not extremely accurate.

Another object of my invention is to provide a condenser chamber of relatively large capacity with an efiicient means for withdrawing refrigerant therefrom regardless of the amount of refrigerant in the'system.

Another object is to rovide an improved method of cooling and condensing the refrigerant by a combination of air and water cooling means.

Another object of this invention is to provide an improved method of opening the electric motor circuit when an excessive head pressure is reached and of relieving said head pressure at the same time.

The above and other objects and the novel features of the invention will be apparent from the following description taken with the accompanying drawings in which Fig. 1 is a vertical sectional view of the apparatus, the regulating valve, thermostat and expansion coils being shown diagrammatically.

50 Fig.2 is a the line 2--2 of Fig. 1, s'howin seal members, the condenser wal s cant separator.

horizontal sectional view, on the liquid and lubri- Fig. 3 is a sectional view, one line 33 of Fig. 1, showing the rotary gear pump and lubricating passages, an

Fig. 4 is an enlarged detail view of the refrigerant liquid inlet to the conducting system, showing the float and the screen associated therewith.

The refrigerating apparatus, as herein shown, comprises a refrigerant conducting system including a refrigerant chamber or condenser C, a liquid refrigerant conducting pipe 10 leading to a pressure regulating or expansion valve E which opens into evaporating means comprising refrigerating or expansion coils R which may or may not be immersed in a brine tank, indicated at B. A conducting pipe 11 is provided for returning the expanded refrigerant to the compressor P, where the gas is compressed, and discharged therefrom into a discharge pipe 12 and the lubricant separating trap T. The separated lubricant then passes by pipe 13 into the condenser or lubricant chamber C, and the warm gaseous refrigerant passes upward through pipe 14 into the condensingv coils C. where it is condensed and is discharged substantially as a liquid into the condenser C. My preferred construction involves the use of a refrigerant such as ethyl chloride anda lubricant of heavier specific gravity such as glycerin, thus securing a natural separation in the condensing chamber C, but I do not wish to be limited to this construction as it is entirely practical by slight changes in the arrangement of parts, to use a refrigerant of heavier specific gravity than the lubricant.

The compressor for circulating the refrigerant may be of any suitable rotary type and as best illustrated in Fig. 3, is a gear pump comprising two meshing gears 15 and 16. Gear 15 is driven by a vertical shaft S, which passes upward through the'condenser C and is surrounded by the liquid sealing means S, to be described in detail later. Power is furnished to the shaft S by a vertical electric motor M mounted above and axially in line with the shaft S and supported by the outer member of the liquid seal S. The vertical tubular casing G is concentric with the shaft S and surrounds the condensing coils C which are coaxial with said shaft and said casing.

The refrigerant and lubricant chamber C may be a suitable hollow casing provided with 3 or more legs L, supporting the same, together with the other parts of the apparatus, which in turn are secured to the chamber C. Suitable noise and vibration deadening material may be inserted between the chamber and the legs, or between the legs and the floor, or both places, but as illustrated I have merely shown rubber blocks 18 at the lower ends of the legs.

The chamber C is closed and sealed at the top by a cover 19, which has a central opening 20 through which the sealing means S and drive shaft S extend into the chamber C. The outer member of the sealing means is joined to the cover to provide a gas-tight joint there-between, as at 20.

The lower ends of the shaft S and the sealing means S are supported and guided in a base casting 21, which in turn is fitted in an annular ring 21 in the bottom of the chamber C. The sealing means S is arranged to seal the chamber C from the atmosphere adjacent the point of entry of the shaft S into the chamber. This point of sealing varies with the pressure within the chamber C and it should be understood that the sealing liquid is between the outer atmosphere and the gaseous or liquid contents of the condenser chamber, The sealing means consists of two interfitting members, which have sealing material between them, and in my preferred construction as best shown in Figs. 1 and 2, these interfitting members consist of two telescopically arranged tubular members, one of which is stationary and comprises an outer tubular part.22 that is connected to the base 21 at 22, and an inner tubular part 23 that is spaced concentric with and joined at its lower end to the outer tubular part 22, thereby forming an annular container for liquid sealing material, such as the mercury 24. The height of this container depends on the pressure to be re tained within the chamber C, and if a sealing liquid such as mercury is employed, the depth will be approximately 2" for every pound per sq. in. to be retained, plus any desired additional height. The other interfitting member of the sealing means consists of a skirt tube 25 having its upper end secured to a collar 26 that is mounted on the shaft to rotate therewith, the collar and skirt tube respectively having gas-tight seals with the shaft and with each other. The skirt tube 25 depends into the space between the parts 22 and 23 of the stationary tubular member and the lower end thereof extends a substantial distance into the mercury 24. Adjacent its point of connection to the collar 26, the tube 25 is provided with circular corrugations 25 which render the skirt tube resilient or flexible at this point so that it may automatically align itself with the parts 22 and 23 of the stationary tubular member. Other means of obtaining such self alignment may of course be adopted.

,In order that the shaft S may be kept in substantial alignment with the inner stationar tubular part 23, a bushing 27 is fitted 1n the upper end of said parts 28 and around the shaft S.

In the machine shown, a lubricant is employed which is heavier than the refrigerant and accordingly lies in the bottom of the chamber G. The bodv of lubricant communicates with the space between the shaft S and the inner tubular part 23 through a port 28 in the base 21. The lubricant being un der the pressure of the refrigerant corresponding to its temperature is caused to pass upward along the shaft S and to lubricate the bushing 27. The lubricant which passes the bushing is prevented from passmg into the atmosphere by the liquid seal or column of mercury between the inner sta tionary tubular member and the skirt tube. A helical groove 29 is provided on the shaft S which tends to cause a downward movement of the lubricant and a resultant upward movement of the column of mercury just referred to. This tendency is such as to resist the pressure within the chamber U, which is itself increased to a certain extent by the motion of the refrigerating ma chine parts. A helical groove 30 is also provided, preferably near the upper end of and inside the outer stationary tubular part 22, which groove acted upon by the mercury if caused to revolve b the motion of the skirt tube, sets up a tendency to cause downward movement of the mercury between the outer tubular member and the skirt tube, again resisting the pressure transmitted from within the chamber 0. Lubricant may also be supplied to the space between the outer tubular part 22 and the skirt tube 25 and, because of its lighter specific gravity, will remain on top of the mercury and assist in resisting the pressure in chamber C, and lubricate bearing parts accessible thereto.

The base 21 is provided with a port 31 that establishes communication between the body of lubricant in the chamber C and a bearing 32 in said base for the lower end of the shaft S. A thrust bearing 32' is provided above the bearing32 for taking the weight of the shaft S. A portion of the shaft extending downward through the condenser G into the compressor P, is provided with a helical groove 33 for the purpose of positively feeding the lubricant into the com- 1 pressor. This shaft may be inade of bakelite is clamped a plate 34 of heat insulating material, such as fibre or bakelite, which has, an opening for the shaft S, aligned with bearing 32. As best shown in Fig. 3, the under side of this plate 34 is provided with a groove 35 leading from the hole in the plate 34 to a point immediately above the meeting teeth of the gears 15 and 16 and within the discharge chamber of the compressor P. The above arrangement provides a simple and efficient means for positively feeding lubricant from chamber C and depositing it into the discharge side'of the ear pump above the gear teeth about to mes 1, insuring quiet operation of the gears and gas tightness at the meeting faces of the teeth.

The lubricant once in the compressor P, is carried around by the geanteeth into the suction side and again aroun into the discharge side of the compressor and is ultimately carried out of the compressor along with the compressed gaseous refrigerant through pipe 12 into the lubricant trap or separator T. In thistrap the lubricant is separated from the gaseous refrigerant, the lubricant returning to the chamber C through the pipe 13. The trap T is herein shown somewhat diagrammatically, and it will therefore be understood that other types of more eflicient construction may be employed. The gaseous refri erant discharges from the trap T through tile pipe 14 into the condensing coils C, where the larger portion of the gaseous refrigerant condenses and is discharged as a liquid, together with the uncondensed refrigerant, through the outlet end 36 of the coils into the condenser chamber C, where the liquid refrigerant floats on the surface of the lubricant and the uncondensed gaseous lubricant occupies the space above the surface of the liquid refrigerant and may be condensed by contact with the walls of the condenser. The condensing coils C are formed in the usual manner as a continuous helical pipe and are supported by an annular bracket 37 that is carried by the inner side of the casing or shell C, the lower end of which is supported on the upper end of the condenser C and which extends upwardly about the coils C and the apparatus associated therewith and forms a closed space about such coils through which air may be circulated, the casing G being provided with air inlet openings 39 near its lower end and air outlet openings 40 near its upper end just below the motor M. The cooling air may be circulated through the casing G and past coil C as a natural draft, or a fan F may be provided for inducing an upward draft of the air, the fan being desirably mounted on the drive shaft S in the space above openings 40 in the casting 40" and within the radial openings 40. Additional means may be provided to obtain a more effective cooling of the coil 0 as for example i of the blanket by capillary action. The

the incoming air over the surface such as water, so as to lower the temperature of the,air, and furthermore by drawing such air through porous material that will absorb or hold cooling liquid such as water. A receptacle adapted to contain water for cooling urposes may be carried on the top ofthe con enser 0 adjacent the openings 39 so as to cool the incoming air, but it will be understood that a water container arranged adjacent the outer sides of the openings 39 may serve this purpose equally well. n closed, the top of the condenser C is formed so as to provide an annular water receptacle 42 for maintaining a body of water having a large evaporating surface adjacent the inlet openings 39 and a blanket 43 of suitable-porous and absorbent material is suspended as at 43 from the enlarged upper ortion 22" of the outer tubular seal memer 22. The lower end of the blanket 43- dips into the water in the container 42, which water will be carried upwardly into the liody ower end of the blanket 43 is provided with openings or inwardly extending slots 43" extending above the level of the water in the container 42 and providing openin for admitting the air into the space wlthin the blanket 43, from whence the air passes through the blanket across the coils and upwardly past the fan F and outof the casing 38 through the openings 40. The lower end of the blanket 43 may be secured to the inby drawin of a liqui ner edge of the lower side 37 of the bracket,

37 the latter serving to deflect the inflowing air over the surface of the water in the receptacle 42 and through the openings 43". The inflowing air will thus take up the moisture from the body of water reducing the temperature of the water .and air, and as the latter travels up through the blanket 43, its temperature will be further reduced and thus a more effective cooling of the coils C will be obtained. Furthermore, the evaporation of the liquid in the receptacle 42 on the cover of the condenser C, lowers the temperature of the said cover and assists in cooling the refrigerant thus reducing the refrigerant head pressure. Suitable water supply means, such as a water supply pipe and float valve, may be provided to maintain a supply of water in the receptacle 42.

As there is always gaseous refrigerant in the chamber C above the liquid therein, and as the level of the refrigerant liquid in the chamber C may vary from time to time, it is desirable to insure that refrigerant liquid will always be drawn into the pipe 10. One way of accomplishing this purpose is to always keep the inlet end 10 of the conduct ing pipe 10 a substantially slight distance below the level of the refrigerant liquid. As best shown in Figs. 1 and 4, the inlet end the particular arrangement dis sired substances, whether solids or li 10'? is flexibly connected to the main conducting pipe 10 as by a coil portion 10" thereof which is disposed in the chamber 0 between the inlet end 10 and the point where the pipe 10 enters the chamber, in the present arrrangement, through the cover of the chamber. The extreme end of the refrigerant pipe adjacent the inlet 10' passes through and is secured to a hollow float 44, the said float being adapted to rise and fall with the level of the liquid refrigerant and hold the inlet end 10' substantially a predetermined distance below the surface of the refrigerant. The flexibility of the coil 10" allows the free rise and fall of the float with the level of the liquid refrigerant, and by this means refrigerant will always be supplied to the conducting system, as long as there is at least a thin layer on the surface of the lubricant within the chamber C. In the installation of the machine and during its operation, foreign and other undesirable substances may collect in the chamber C and in the circulation of the refrigerant, such substances including lubricant may enter the conducting system and clog the same or otherwise undesirably affect the system so as to produce an ineflicient interchange of heat therewith from the refrigerating coils thereto. It is, therefore, important that undiem s, be excluded from the refrigerant that e nters the conducting system. In the present arrangement, this is effectively accomplished 'by arranging a screen around the inlet end 10'. The screen may be of any suitable material that will exclude the undesired substances, but allow the refrigerant liquid to enter the conducting system and may be disposed in any suitable manner about the inlet end 10 but preferably the screen is of convex shape and suitably secured to the underside of the float 44 and around the inlet end 10. It will be understood that the pipes 10 and 36 are provided with gas-tight seals at the point where they enter the chamber C.

Upon a failure of the air circulating system or for other reasons, an excessive head pressure may be built up in the chamber C, and in order that no damage shall result from such pressure, it is desirable that the operation of the compressor be stopped automatically. The simplest way to accomplish this is to open the circuit which supplies current to drive the electric motor, and the opening of this circuit in response to a predetermined or excessive pressure in the system may beaccomplishedin various ways. Inasmuch as the sealing mercury in the seal S is, at its inner end, subject to the pressure within the chamber C, I employ this sealing liquid as a means in combination with a float switch operated thereby to open the motor circuit. In the arrangement illustrated, the upper enlarged end 22" of the outer stationary sealing tube 22, forms a chamber for an annular float of suitable buoyant material such as cork. The float 50 carries a. metal conducting member or switch 51 here shown in the form of an annular' ring and when the float is in its normal or lowermost position, is adapted to engage ledges on the lower ends of the terminals 52 and 5gwhich are electrically connected to the conductors 54 and in series with the motor circuit. and 53 are stationary, being mounted on, but insulated from the casting 40 which is connected by brackets to the upper enlarged end 22' of the stationary tubular sealing member 22. Accordingly, when excessive pressure is built up in the refrigerant system and in the chamber 0, the liquid in the space between the telescopic members of the sealing tubes will be forced into the float chamber, lifting the float 50 and the switch member 51 thereof out of engagement with the electric terminals 52 and 53 and thus openin the motor circuit. Normally, the motor circuit is established with suitable electric supply mains through the conductor 54, the terminal 52, switch member 51, terminal 53, conductors 55 and 56, motor windings, conductor 57, thermostat 58 to the other one of the electric current supply mains. The motor circuit will, of course, then remain open at this point until the pressure in the system is reduced. 7

In order that the excess pressure in the system shall be automatically relieved and the system restored to operative condition, I provide means for relieving the pressure in the high pressure or compression side of the system, by transferring a small amount of the compressed gas directly from the high pres sure portion of the conducting system to the low pressure portion of the conducting system. In the arrangement disclosed, a suitable relief valve V, made gas-tight to the atmosphere by a casing 68, is provided which has a valve member 59 carried by a stem 60 that controls a passage 61 surrounding the stem which is adapted to establish communication between a branch pipe 62 connected to one of the condensing coils C, and a branch pipe 63 that is connected to the suction pipe 11. When the valve 59 is raised, gaseous refrigerant will pass from the coil G through the pipe 62, passage 61 and tion pipell. The valve 59 is arranged to be automatically and electrically operated after the float switch has been opened, a magnet 64 being provided for this purpose and connected across the float switch terminals 52 and 53 by conductors 65 and 66. The electromagnet 64 is adapted to operate the valve 59 through an armature 67 that is carried by the valve stem 60 and the magnet 64 is so wound that normally, when the motor is operating, insuflicient current will flow The terminals 52- pipe 63 to the sucthrough the electromagnet windinglto at-,

t e float" switch is opened, the winding 64 being in parallel wil tract the armature 67, but when be in series with the motor, enabling the magnet to attract the armature 67 and open the valve 59 thereby relieving the head pressure in the stem and discharging the refrigerant intoit e suction side of the system. The windings of magnet 64 is of high enough resistance to prevent the rotation of the motor while the float switch is open. Of course, it will be understood that instead of dischar 'ng the refrigerant into the suction side 0 the stem, such refrigerant may be discharged into the atmosphere but by this means refrigerant will be lost from the system and is, therefore, in somerespects not as desirable as discharging the high pressure refrigerant into the suction side of the system and thereby retaining all of the refrigerant in the conducting system. Other electrical means may be emloyed for controlling the motor and the reief valve V, such as a relay circuit in series with the thermostat relay circuit, thus obviating the necessityof opening the relatively high voltage mam circuit at the float switch.

. tween said motor and I claim:

1. In refrigeratin apparatus, the combination of a vertica casing having air inlet and outlet openings, a vertically disposed motor carried thereby, a rotary com ressor carried by said casing, a vertical 'riving shaft connecting vsaid motor and said compressor, condensingmeans including coils carried by said casing coaxial with sai shaft and said casing, and a fan on said shaft besaid compressor and between said inlet and outlet openings arranged to circulate air past said coils.

2. In, refrigerati a paratus, the combination of a vertica tu ular casing having air inlet and outlet openings, a vertically disposed motor carried thereby, a rotary compressor carried by said casing and connected with the armature shaft of said motor, a vertical driving shaft connecting said motor and said compressor, a refrigerant and lubricant collecting chamber, condensin-g coils coaxial with and carried by said casing communicating with said compressor and discharging into said chamber, means for conducting lubricant from said chamber to said compressor, and a fan between said motor and said compressor arranged to circulate air past said coils.

3. In refrigerating apparatus, the combination of a refrigerant and lubricant collecting chamber, a compressor, means for conducting lubricant from said chamber to said compressor, condenser means communicating with said compressor and discharging into said chamber, a fan for circulating air across said condenser means, and a motor drive having a shaft said compressor and conducting ubricant from said chamber to said compressor,' condenser means communicating with said compressor and discharging into said chamber, a fan for circulating air across said condenser means, a motor, a vertical drive shaft coupled to said motor and fan and 1projecting into said compressor, and fluid-tig t sealin means surrounding said shaft between sai fan and'said compressor said chamber, condenser means and verti drive shaft being coaxial with one another.

5. In refrigerating apparatus, the combination of a chamber adapted to contain liquid refrigerant and lubricant, condensing means communicating with said chamber, a vertical rotary compressor communicating with the body of lubricant in said chamber, refrigerant evaporating meanscommunicating with the body of refrigerant in said chamber and the suction side of said compressor a vertical electric motor, a vertical aft connecting the armature of said motor to the rotor of said compressor, a fan on said drive shaft adapted to circulate air adjacent said chamber and vertically across said condensing means, and means connecting the discharge side of said compressor to said chamber and to said condensing means.

6. In refrigerating apparatus, the combicludin refrigerant and lu ricant of different-s means for circulating refri rant through said system including a sha t entering said condenser throu h a wall thereof means for sealing said condenser adjacent the point of entry of said shaft comprising telescopically arranged spaced tubular members, one of which is stationary and which extendsalon said shaft and the other of which is secured fic gravities,

ion nation of a refrigerant conducting system. in-

to said shaft to move therewith and extends along the shaft outside said stationary tubular member and spaced therefrom, a sealin substance in the space between said tubu lar members, a bearln on one end of the stations tubular mem r for said shaft, and a In ricant passage from the lubricant in said condenser to said bearing.

.7. In refrigerating apparatus, the combination of condensing and evaporating means including a chamber for containing lubricant, means for circulating refrigerant comprising a compressor and driving means for said compressor passing through a wall of said chamber, and means for sealing said chamber adjacent the point of entry of said driving means comprising interfitting members, sealing material between said members, and means whereby one of said members is flexibly connected to a part of the apparatus upon which it is mounted.

8. In refrigerating apparatus, the combination of a chamber for containing lubricant, an evaporator communicating therewith, a condensing coil mounted above and discharging into said chamber, a compressor mounted below said chamber, power means for driving said compressor mounted above said condensing coil, a drivin shaft connecting said power means to said compressor and passing through said coil and said chamher, and means for sealing said chamber adjacent the point where said driving shaft enters it.

9. In refrigerating apparatus, the combination of a refrigerant conducting system including a regulating valve, expansion coils, a chamber for containing liquid refrigerant and conducting means leading from said chamber to said valve, and having its inlet end disposed below the lever of the refrigerant in said chamber, and means whereby said inlet end is caused to rise and fall with the level of the refrigerant in said chamber, thereby maintaining said inlet end a substantially predetermined distance below the level of said liquid refrigerant.

10. The invention claimed in claim 9 in which said conducting means comprises a pipe having a flexible portion adjacent its inlet end, and a float connected to said inlet end and adapted to cause the latter to rise and fall with the level of the liquid refrigerant.

11. The invention claimed in claim 9 in which said conducting means terminates in a coil of pipe constituting a flexible portion adjacent said inlet end, and a float secured to said coil near said inlet end adapted to cause the rise and fall of said end in accordance with the level of liquid refrigerant in said chamber.

12. In refrigerating apparatus, the combination of a refrigerant circulating system comprising acondenser, an evaporator, a

compressor and a normally closed relief passage for said system, an electric motor for driving said compressor; and means operable to interrupt the o eration of said motor and to open said relie passage when a predetermined pressure develops in said system.

13. In refrigerating apparatus, the combination of a refrigerant conducting system including a compressor and means including a condensing chamber for cooling a refrigerant discharging from the compressor, a wall of said chamber comprising a water container arranged to provide an exposed water surface adjacent the refrigerant cooling means.

14. In refrigerating apparatus, the combination of a refrigerant conducting system including a compressor and means for cooling a refrigerant discharging from said compressor, such cooling means comprising a condensing chamber comprising part of such conducting system and supporting means for carrying a body of water aving its surface exposed for evaporation, said cooling means also comprising a cooling coil mounted above such Water surface and in the path of upward currents of air flowing over said water surface.

15. In refrigerating apparatus, the combination of a refrigerant conducting system including a compressor and means including a condensing chamber for cooling a refrigerant discharging from the compressor, and water containing means comprising a part of the upper wall of the condensing chamber of said refrigerant conducting system, said water containing means being open at the top.

16. In refrigerating apparatus, the combination of a refrigerant conducting system including a compressor and means including a condensing chamber for cooling a refrigerant discharging from the. compressor, and provided with water-containing means, and absorbent material having a portion immersed or dipped into the Water in said water-containing means, a portion of Such absorbent material being in the path of currents of air flowing past said cooling means.

17. In refrigerating apparatus, the combination of a refrigerant conducting system comprising condensing and evaporating means, means for circulating refrigerant in said system, including driving means entering a part of said system through a wall of said part, means for sealing said system adjacent the point of entry of said driving means, and controlling means for said driving means operated by said sealing means when there is a predetermined pressure in the system.

18. The invention claimed in claim 17 in which said sealing means comprises a liguid and said controlling means comprises a cat normally held down by gravity and arranged to be lifted by said sealing liquid when there is a predetermined or excessive pressure in the system. i

19. The invention claimed in claim 17 in which said sealing means comprises a column of liquid having one end subject to the pressure of the refrigerant in said system, and in which said controlling means comprises a float that is normally inoperative but which is caused to rise to control said drivin means when said sealing liquid is forced outwardly due to an excessive pressure in said system.

20. The invention claimed in claim 17 in which said driving means comprises an electric motor, and said controlling means includes an electric circuit opening-and-closing means arranged to cause the motor cirfull cuit to be opened to stop said motor when said sealing means is subjected to an excessive pressure in said system.

21. In a refrigerating apparatus, the combination of a chamber containing lubricant, means for circulating refrigerant including a compressor, condensing and evaporative means in circuit with said compressor, means for driving said compressor including a shaft passing through a wall of said chamber, means for sealing said chamber adjacent the point of entry of said shaft, and pressure relieving means actuated by said sealing means at a predetermined pressure in said chamber.

22. The invention claimed in claim 21 in which the pressure relieving means comprises a relief passage that ischarges into the low pressure portion of the system.

23. The invention claimed in claim 21 in which the pressure relieving means comprises an electromagnetically operated valve sealed to prevent the discharge of pressure into the atmosphere, and in which said sealing means comprises a liquid, in combination with a float operated by said liquid to control the supply of electric current to the magnet which operates said valve.

24. In refrigerating apparatus, the combination of a chamber containing refrigerant and lubricant, condensing means communicating with said chamber, a compressor mounted adjacent the under side of said chamber and communicating with the body of lubricant therein, refrigerant conducting means including a regulating valve and expansion coils between said chamber and the suction side of said compressor, an electric motor mounted above said chamber, means including aivertieal drive shaft connecting said motor to said compressor, packing means for said drive shaft, a fan on said shaft adapted to cause the circulation of air past said condensing means, and means including lubricant separating means, connecting the discharge side of said compressor to said chamber and to said condensing means.

' 25. In refrigerating apparatus, the combination of a condensing chamber for containing refrigerant and lubricant; an evaporator; a rotary compressor in circuit with said chamber and evaporator, and coaxially disposed relatively to said chamber; a conduit whereby lubricant is supplied from said chamber to said compressor; and a separator having an inlet for mixed refrigerant and lubricant and also having a lubricant outlet communicating with said chamber below the normal level of lubricant therein.

26. In refrigerating apparatus, the combination of a condensing chamber for containing refrigerant and lubricant of different specific gravities, with the refrigerant floating upon the lubricant; an evaporator; a conduit leading thereto; a rotary compressor in circuit with said chamber and evaporator and having a vertical shaft disposed substantially axially of said chamber; an electric motor having a vertical drive shaft coupled to said compressor shaft; a conduit communicating with the bearing of the comwith the lubricant in said said compressor is lubriin said chamber for adto the conduit leading to said evaporator; and a separator having an inlet for mixed refri erant and lubricant, and also having a lubricant outlet communicating with said chamber below the level of lubricant therein. l

27. In refrigerating apparatus, the combination of a refrigerant circulating system comprising a condenser, an evaporator, and a compressor in circuit therewith; and electrically controlled means to relieve a predetermined pressure in said system including a relief passage discharging into a low pressure portion of such system.

28. In refrigerating apparatus, the eombination of a refrigerant circulating system comprising condensing coils, an evaporator, and a compressor in circuit with such coils and evaporator; an electric motor for driving said compressor; and means to relieve a predetermined pressure in said coils including a relief passage adapted to discharge refrigerant from said coils into said circuit between said evaporator and said compressor, a valve controlling said relief passage; and means in circuit with said motor for operating said valve.

In testimony whereof, I aflix my si ature.

RAYMOND C. PIE CE.

pressor shaft and chamber whereby cated; float means mitting refrigerant 

